Diagnostics of eosinophilic esophagitis: clinical, endoscopic, and histologic pitfalls

Eosinophilic esophagitis (EoE) is currently defined as an immune-mediated chronic esophageal disorder that is diagnosed using both clinical and pathologic information. A series of consensus diagnostic guidelines for EoE have brought a measure of consistency to the field, but in practice the diagnosis of EoE can be challenging. Typical clinical symptoms of EoE, including dysphagia, heartburn, and chest pain, can overlap with gastroesophageal reflux disease, which itself is a common indication for performing endoscopic evaluation. The endoscopic findings of EoE, such as esophageal rings, strictures, linear furrows, and white exudates, are not specific. Esophageal eosinophilia, the histologic hallmark of EoE, is also not pathognomonic and can be seen in a range of conditions. Further complicating the diagnosis of EoE is the newly recognized entity of proton pump inhibitor-responsive esophageal eosinophilia, a condition that must be excluded prior to confirming a diagnosis of EoE. This paper will review the current diagnostic criteria for EoE and discuss multiple clinical, endoscopic, and histologic pitfalls in making the diagnosis of EoE.